Contents lists available at ScienceDirect Psychiatry Research journal homepage: www.elsevier.com/locate/psychres Gambling behavior in Parkinson's Disease: Impulsivity, reward mechanism and cortical brain oscillations Michela Balconi a,b, ⁎ , Laura Angioletti a,b , Chiara Siri c , Nicoletta Meucci c , Gianni Pezzoli c a Department of Psychology, Catholic University of the Sacred Heart, Milan, Italy b Research Unit in Affective and Social Neuroscience, Catholic University of the Sacred Heart, Milan, Italy c Parkinson Institute, ASST G. Pini-CTO, ex ICP, Milan, Italy ARTICLE INFO Keywords: Pathological gambling Parkinson's Disease Decision making Iowa Gambling Task Electroencephalography (EEG) ABSTRACT Psychopathological components, such as reward sensitivity and impulsivity, and dopaminergic treatment are crucial characteristics related to the development of Pathological Gambling (PG) in Parkinson's Disease (PD). The aim of the present study is to investigate the differences in decision-making in PD patients with or without PG considering both neurophysiological and behavioral aspects. The IOWA Gambling Task (IGT) and electro- encephalographic (EEG) activity were considered to elucidate the decision and post-feedback processes in PG. The sample included fifty-two PD patients, divided in three groups: 17 PD patients with active gambling be- havior (PD Gamblers, PDG); 15 PD patients who remitted from PG (PD Non-Gamblers, PDNG); and a Control Group (CG) composed by 20 patients with PD only. EEG and IGT performance were recorded during decision and post-feedback phase. Results showed worse performance and an increase of the low frequency bands in the frontal area for the PDG group compared to the other two groups. In addition, higher BAS (Behavioral Activation System) and BIS-11 (Barratt Impulsiveness Scale) personality components were correlated to groups’ behavioral response. These results show an anomalous behavioral (IGT) and cortical response of PDG patients related to their inability to use adequate control mechanisms during a decision-making task where reward mechanisms (BAS) and impulsivity (BIS-11) are relevant. 1. Introduction Although Parkinson's Disease (PD) is characterized by well-defined motor control symptoms (such as bradykinesia, akinesia, rigidity, resting tremor and gait disorder), its non-motor features can also occur in the early stages of disease, and are a key determinant of patients’ quality of life (Chaudhuri and Schapira, 2009). Among these non-motor symptoms related to PD are pathological gambling (PG), hypersexu- ality, compulsive shopping and compulsive or binge eating. In parti- cular, the present study focused on pathological gambling behavior, that is defined as an inappropriate, persistent, and maladaptive gaming behavior, and is observed in 1.7–7% of PD patients treated with do- pamine agonists (Weintraub et al., 2015). Nowadays, there is a con- sensus among researchers that PG in PD is considered as effect side of dopaminergic treatment (Voon et al., 2011). Specifically, a greater amount of dopamine agonist (DA) in a partially dysfunctional reward system may provoke a hyper-dopaminergic condition: a situation that disposes to the development of PG in PD (Poletti et al., 2011). Indeed, the dopamine administration can over-excite relatively intact ventral areas, thus promoting strong impulsive behaviors that at first give an immediate reward or pleasure (i.e. gambling, eating, shopping). Then, these impulsive and rewarding behaviors become compulsive and re- petitive habits over time because of an impairment of dorsal striatal circuits that leads to a difficulty in monitoring, controlling, updating and modifying maladaptive behaviors (Van den Heuvel et al., 2010). Thus, to identify and clarify the neural substrates that underlie decision-making may elucidate mechanisms contributing to continued high-risk behaviors in pathological gamblers (Balconi et al., 2014a,b). At least two underlying types of dysfunctions have been identified where reward signals turn in favor of immediate outcomes in the case of decisions: (1) hyperactivity in the emotional system, mediated by frontal and medial structures such as the Orbitofrontal Cortex (OFC), Anterior Cingulate Cortex (ACC) and amygdala, which exaggerate the rewarding impact of external reinforcers, and (2) hypoactivity in the prefrontal cortex (such as left ventromedial areas, vmPFC, and mainly the dorsolateral prefrontal cortex, DLPFC), which predicts the long- term consequences of a given action and that is a critical component for working memory and executive processes. Damage or dysfunctional conditions to either of these systems can alter the normal functioning of the decisional processes (Balconi et al., 2014b). https://doi.org/10.1016/j.psychres.2018.03.041 Received 5 October 2017; Received in revised form 5 February 2018; Accepted 18 March 2018 ⁎ Corresponding author at: Department of Psychology, Catholic University of the Sacred Heart, Largo Gemelli, 1, Milan 20123, Italy. E-mail address: michela.balconi@unicatt.it (M. Balconi). Psychiatry Research xxx (xxxx) xxx–xxx 0165-1781/ © 2018 Elsevier B.V. All rights reserved. Please cite this article as: Balconi, M., Psychiatry Research (2018), https://doi.org/10.1016/j.psychres.2018.03.041